1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device and to a semiconductor device. The present invention is suitably applied to a semiconductor device, such as a light emitting diode using a nitride-based III-V compound semiconductor, for example.
2. Description of the Related Art
When crystal growth of a nitride-based III-V compound semiconductor, e.g., a GaN-based semiconductor, forming a device structure, is developed on a sapphire substrate, it has hitherto been general to first grow a buffer layer, which is made of GaN or AlN, on the substrate (see, for example, H. Amano et al., Appl. Phys. Lett. 48,353(1986); I. Akasaki et al., J. Cryst. Growth 98,209(1989); K. Hiramatsu et al., J. Cryst. Growth 115,628(1991); Hiroshi Amano and Isamu Akasaki, OYO BUTURI (Applied Physics) 68,768(1999); and I. Akasaki, J. Cryst. Growth 221,231(2000)). By growing a nitride-based III-V compound semiconductor layer after growing the buffer layer on the sapphire substrate, as described in those documents, threading dislocation generated in the nitride-based III-V compound semiconductor layer can be reduced even when lattice mismatching between the sapphire substrate and the nitride-based III-V compound semiconductor is large. As a result, the nitride-based III-V compound semiconductor layer having a flat surface and good crystallinity can be obtained.